Field of the Invention
The present invention relates to intervertebral disc prostheses, and more particularly to a lordotic interbody spacer that is adjusted or expanded in situ to occupy desired space between vertebral bodies.
Description of the Related Art
Spinal fusion is a surgical technique used to facilitate the growth of bone between two vertebrae. The procedure involves implanting a spacer, such as an interbody device, for example, packed with grafting material into the disc space to stabilize the spine while bone grows in between two vertebrae. As the bone graft material heals, one long bone is formed with the adjacent vertebrae. The purpose is to eliminate movement between the vertebrae to reduce pain and nerve irritation.
An interbody fusion may involve removing the intervertebral disk. When the disk space has been cleared, the interbody device is implanted between the two adjoining vertebrae. These devices may contain the bone graft material that promotes bone healing and facilitates the fusion. After insertion, surgeons may use (e.g., bone) screws, plates, and rods to further stabilize the spine. Interbody fusion can be performed using a variety of different approaches, and, in an anterior lumbar interbody fusion, the procedure is performed from the front of the patient.
Lordotic angle is the angle between the top (superior surface) of the second lumbar vertebra and the bottom (inferior surface) of the fifth lumbar vertebra, used as a measurement of the curve of the lumbar spine. In some instances, it might be desirable to adjust or otherwise set the lordotic angle during the spinal fusion operation to adjust lordosis of the spine.